The Left has traditionally assumed that human nature is so malleable, so perfectible, that it can be shaped in almost any direction. By contrast, a Darwinian science of human nature supports traditionalist conservatives and classical liberals in their realist view of human imperfectibility, and in their commitment to ordered liberty as rooted in natural desires, cultural traditions, and prudential judgments. Arnhart's email address is larnhart1@niu.edu.

Monday, May 25, 2009

Life is good. Especially if you're staying in a mews house in London's Knightsbridge a few blocks from Harrods with great restaurants all around.

Today I visited Darwin's house in the village of Downe for the first time. This was fascinating. Darwin lived here with his family for 40 years, from 1842 until his death. Here is where all of his writing was done. So it gives us a lot to ponder about the conditions for such serious intellectual work.

It's impressive to see the evidence of a rich family life that did not impede his work. Seven of his ten children lived to adulthood. He expanded his house to accommodate them. They were free to enter his study. He used them to help in his experiments. This was a home full of life and energy, although it was darkened by the deaths of the three children and by Darwin's strange persistent illness.

For me, there were three highlights. First, the small, modestly arranged study indicated how much good work can be done by someone who thinks and writes consistently over many years, relying on visits from his friends and an extensive network of correspondents to provide information and ideas. From reading his early notebooks from the late 1830s and early 1840s, one can see that he had laid out all of his fundamental issues before he married Emma and moved to Down. Then, for the rest of his life he devoted himself to resolving those issues that had arisen during his trip on the Beagle and during his first few years back in England.

Second, the greenhouses and gardens were surprising to me because they showed how extensive his botanical experiments were, and how important this was for his work. He wrote important books on orchids and insectivorous plants.

The third highlight was the sandwalk. This is the path around one part of his property where he walked a few times each day. The sandwalk makes a long oval around a lovely copse of trees. The story is that he started each walk with a problem to solve. He would pile up some pebbles at the beginning of the path. As he completed each round of the path, he would kick off a pebble. Then, once he had thought through the problem he was pondered, he would count the pebbles to see how many rounds on the sandwalk had been required. He could then rank his problems--a 4-pebble problem one day, a 5-pebble problem the next. These are the habits of a thinker.

I also thought about the social conditions that made Darwin's life and work possible. He lived his whole life relying on his inherited wealth, supplemented with the royalties from his publications. Living as a country gentleman, he employed household servants to manage the house and the grounds. This is a life that few can live today.

In the parish church graveyard, I noticed the grave stone for Darwin's life-long servant. The stone read: "In memory of Joseph Parslow, who died October 4, 1898, aged 86 years, the faithful servant and friend of Charles Darwin of Down House, in whose household he lived for upwards of 36 years." The modesty of this grave contrasts with the grandeur of Darwin's burial in Westminster Abbey, near the grand monument to Isaac Newton.

Tuesday, May 19, 2009

Articles in The Guardian in London announced today a remarkably well-preserved fossil--named Ida--that is being interpreted as the "missing link" between the primate line that led to human beings and other mammalian species. The full scientific report is available at PLoSONE.

It is good to be cautious about such announcements until lots of folks have had the chance to examine the fossil and debate its significance. My suspicions are aroused by the elaborate media campaign associated with the announcement of this fossil.

But this does seem to one of the most complete primate fossils ever discovered. This reminds us of how skimpy the primate fossil record is. Still, this also reminds us that there really is a discoverable fossil record that provides a factual basis for Darwinian evolutionary theory.

In fact, the evidence for the evolution of the human species from ancestral primate species is so clear that even proponents of "intelligent design theory" like Michael Behe admit that here the evidence for human evolution is convincing.

In the Introduction to his Treatise of Human Nature, David Hume lays out his grand vision of a comprehensive science grounded on a science of human nature. All the sciences depend upon the knowledge of human nature, he argues. Even mathematics and the physical sciences depend on a science of human nature in so far as these sciences are objects of human study and are judged by human thought. He proposes that this science of human nature can be developed through the "experimental method of reasoning." And yet the "experiments" necessary for moral science cannot be controlled as they are in the physical sciences. "We must therefore glean up our experiments in this science from a cautious observation of human life, and take them as they appear in the common course of the world, by men's behaviour in company, in affairs, and in their pleasures. Where experiments of this kind are judiciously collected and compared, we may hope to establish on them a science, which will not be inferior in certainty, and will lie much superior in utility to any other of human comprehension."

Darwin's development of evolutionary science allowed for the fulfillment of this Humean project of a comprehensive science of human nature. Hume had already anticipated the theoretical possibility of Darwinian evolution. For example, Philo in Hume's Dialogues Concerning Natural Religion speaks of the possibility of the evolutionary natural selection of worlds and organisms. Darwin adopted this idea of evolution from Hume, Smith, and other Scottish philosophers and elaborated the scientific evidence and arguments for it.

Every topic that I have taken up on this blog could be understood as part of this Humean science of human nature rooted in Darwinian evolutionary science. This science could be sketched out according to at least ten broad themes running through my blog posts: (1) Darwinian liberal education, (2) deep history, (3) ethology, (4) behavioral game theory, (5) neuroscience, (6) social history, (7) moral psychology, (8) evolution of religion, (9) evolutionary aesthetics, and (10) the Darwinian future of human nature.

(1) DARWINIAN LIBERAL EDUCATIONHume's comprehensive science of human nature corresponds to what Edward O. Wilson calls "consilience" and to what I call "Darwinian liberal education." The simple idea is the unification of knowledge through evolutionary reasoning, which would unify the natural sciences, the social sciences, and the humanities.

The evolutionary reasoning would have to move through at least three levels of evolutionary history--genetic evolution, behavioral evolution, and symbolic evolution. Like all forms of life, the human species has arisen from a history of genetic evolution. Like other animals with behavioral traditions of learning, the human species has a history of behavioral evolution. Although other animals can think, learn, and communicate, human beings are unique in their capacity for symbolic conceptualization, which supports a history of symbolic evolution. Consequently, a Humean and Darwinian science of human nature depends on a coevolutionary theory of the complex interaction of three systems of inheritance--genetic, behavioral, and symbolic.

(2) DEEP HISTORYThis science of human nature is a science of deep history in the sense that it views human history as part of the whole history of the universe and life. The proper study of history, Hume claims, should allow us "to see all human race, from the beginning of time, pass, as it were, in review before us; appearing in its true colours, without any of those disguises, which, during their life-time, so much perplexed the judgment of the beholders." And so, "a man acquainted with history may, in some respect, be said to have lived from the beginning of the world, and to have been making continual additions to his stock of knowledge in every century" ("Of the Study of History").

Like John Locke, Hume believed that "in the beginning, all the world was America." In other words, the reports from the New World about the American Indians who lived as hunter-gatherers could be interpreted as showing how human beings had lived in the earliest savage societies. Once they began to herd animals, human beings moved into pastoral societies. Then, with the emergence of agriculture, they entered into agrarian societies, which have dominated written human history since the invention of writing. Most recently, modern human beings have entered commercial societies that sustain larger populations and more progress in the arts and sciences than had hitherto been seen.

Although European historical thought was dominated by a Biblical history that assumed that human beings appeared first about 6,000 years ago, Hume suggested that human history was probably much older than that. But it was not until the 19th century that research in geology, archaeology, and paleoanthropology indicated that the earth and humanity were much older than suggested by the Biblical timescale. By the 1860s, John Lubbock and others were able to show the prehistoric ancestry of the human species, which supported Darwin's account of human evolution in deep time.

Most recently, historians like David Christian and Daniel Smail have argued that the very idea of "prehistory" is misconceived, because it reflects a legacy of Biblical history, and instead we should look to science as supporting a deep history that embraces the entire evolutionary history of humanity within the natural history of the earth and the universe.

(3) ETHOLOGYIn his study of human nature, Hume repeatedly relies on comparisons with other animals, because "the lives of men depend upon the same laws as the lives of all other animals," and "all animals are entrusted to their own prudence and skill for their conduct in the world" ("Of Suicide"). The study of human thinking, feeling, and learning is illuminated by comparisons with other animals that have similar mental and behavioral capacities. In Darwin's earliest notebooks, we can see his notes on these writings of Hume comparing human beings and other animals.

Though the scientific study of animal behavior goes back as far as Aristotle, the methodical study of animal behavior--ethology--has seen its greatest advances over the last 50 years. In particular, the work of primatologists like Jane Goodall and Frans de Waal makes it clear that many primate groups show cultural traditions of behavioral learning that constitute the unique cultural history of each group. This research also makes it clear that each animal has a unique personality that manifests the inborn temperament and individual history of the animal. Thus, the individuality and historicity of human life characterize animal life generally. Consequently, all animals must exercise something like judgment in deciding how to conduct themselves in navigating their way through the complex physical and social world in which they find themselves.

(4) BEHAVIORAL GAME THEORYOne of Hume's most insightful ideas is how cooperation evolves gradually through conventions without explicit design by which human beings become conditional cooperators. People see that it is mutually beneficial to cooperate as long as they are sure that others are cooperating and not cheating. As people interact over time, they develop trust in one another, which supports their continued cooperation. Languages evolve in this way. And so do institutional practices like property, contracts, and allegiance to government. Groups with cooperative members will tend to prevail over groups with lots of cheaters.

These traditions of cooperation are fragile, and they can fail as people collapse into a Hobbesian war of all against all, because human selfishness can always tempt people into cheating. This tense balance between cooperation and conflict manifests the mixed motives of human nature, in which there is, as Hume says, "some particle of the dove, kneaded into our frame, along with the elements of the wolf and the serpent."

Hume's story of the gradual evolution of cooperation was continued by Darwin and elaborated into a formal theoretical format in modern behavioral game theory. Experiments in game theory have shown that human beings are both selfish and social, and these experiments have shown the conditions required for the emergence of cooperation even among people with "elements of the wolf and the serpent." Evolutionary game theory has shown how this might happen through the evolutionary history of group selection. One advantage of such game theory is that experiments in game theory can be conducted with groups of people to test predictions, and in recent years such experiments have been conducted with groups of people around the world in diverse kinds of societies. So here is an example of the "experimental method" in the science of human nature.

(5) NEUROSCIENCEIn his essay "Of the Immortality of the Soul," Hume concluded from the evidence of natural experience: "Every thing is in common between soul and body. The organs of the one are all of them the organs of the other. The existence therefore of the one must be dependent on that of the other." From the seventeenth century, the work of the first neurologists such as Thomas Willis had indicated that the brain was the primary part of the body supporting the soul or mind. Darwin believed that the evolution of the human mind depended on the evolution of the brain.

Recent advances in the science of the brain make neuroscience crucial to any science of human nature. The conclusions of neuroscience support the claim that the unique intellectual and moral freedom of human beings arises from the emergent evolution of the soul in the brain. It still remains somewhat mysterious, however, as to whether the science of the brain can fully account for our introspective experience of self-conscious awareness in our thinking, feeling, and willing.

In any case, neuroscience does seem largely to confirm Hume's psychological observations. For example, Hume argues that in sympathy the human mind becomes a mirror to the thoughts and feelings of others. Adam Smith elaborated this idea of sympathy as sustaining moral sentiments. Now the research on "mirror neurons" suggests a neurological basis for this.

(6) SOCIAL HISTORYHume's science of human nature is a historical science, because he thought that the record of human history was "so many collections of experiments" from which the philosopher could infer a science of human nature in both its uniformity and diversity.

Hume's History of England is a massive 6-volume history of England from Julius Caesar's invasion in 55 BC to the Revolution of 1688. Although he emphasizes the history of government, Hume's history includes every aspect of English society, including morals, manners, economics, religion, technology, science, and the arts. Like Aristotle's study of regimes, Hume's history of England is a history of the whole way of life of the English people. Like Aristotle's study of the best regime, Hume's essay "The Idea of a Perfect Commonwealth" sketches a model of a perfect form of government that reflects the historical experience of England in balancing liberty and authority. Subsequently, as Douglas Adair has shown, this Humean conception of politics influenced James Madison, Alexander Hamilton, John Adams, and others at the American founding.

This idea of social history is so broad as to embrace many topics bearing on human history as an experimental record of human nature. For example, Hume was a moral critic of slavery, and he saw the history of the debate over slavery as manifesting the moral history of human nature.

(7) MORAL PSYCHOLOGYHume is famous--if not notorious--for insisting that morality is more a matter of passion than of reason, because reason by itself cannot move us to act. In the Treatise of Human Nature (II.iii.3), he writes: "We speak not strictly and philosophically when we talk of the combat of passion and reason. Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them. . . . Where a passion is neither founded on false suppositions, nor chooses means insufficient for the end, the understanding can neither justify nor condemn it. It is not contrary to reason to prefer the destruction of the whole world to the scratching of my finger. It is not contrary to reason for me to choose my total ruin, to prevent the least uneasiness of an Indian or person wholly unknown to me. It is as little contrary to reason prefer even my own acknowledged lesser good to my greater, and have a more ardent affection for the former than the latter. . . . In short, a passion must be accompanied with some false judgment in order to its being unreasonable; and even then it is not the passion, properly speaking, which is unreasonable, but the judgment."

One should notice, however, in this passage that reason is important to moral experience because the moral passions depend on judgments about the world that can be either reasonable or not. But Hume stresses the primacy of moral passions to counter the excessive rationalism of those moral philosophers who assume that morality arises as a deduction of pure reason. Determining what is right or wrong is not a matter of rational proof but of natural feeling.

In Darwin's account of the evolution of morality, he followed the lead of Hume, Smith, and other Scottish moral philosophers in emphasizing the importance of moral emotions in expressing the human moral sense as rooted in evolved human nature.

In recent years, there has been a growing movement among some philosophers, biologists, and psychologists that Hume and Darwin were right about the moral psychology of the emotions as founded in the moral instincts of human nature.

(8) EVOLUTION OF RELIGIONA science of human nature must include some explanation of the almost universal human inclination to religious belief and practice. One explanation might be that human beings have adopted religion through some some kind of rational proof--as in the testimony for the reality of miracles or in reasoning from the natural design of the universe to the existence of a divine designer. Hume lays out his reasoning for why one should be skeptical about each of these lines of reasoning, although in principle he is open to such reasoning from experience for the truth of religion.

Whether or not one is persuaded by the theological truth of religion, one must explain the psychological dispositions of human nature that incline human beings to religion. Does religion satisfy transcendent longings for immortality and redemption? Does it answer existential questions about the meaning of human anxiety before death and suffering? Does it explain the ultimate cause of the order of nature that eludes secular reason? Does it provide support for morality by organizing human beings into cooperative groups bound together by a common purpose?

Alfred Russel Wallace shared with Darwin the distinction of developing the idea of evolution by natural selection. But unlike Darwin, Wallace believed that religion (along with art and science) manifested a spiritual reality in human nature that could not be fully explained by natural evolution. Evolutionary theorists today continue this debate over how or whether evolutionary science can provide a naturalistic explanation for religion.

And, of course, much of the popular debate over Darwinian science turns on the question of whether it necessarily promotes atheism, or whether it is open to the intellectual and moral claims of religion.

(9) EVOLUTIONARY AESTHETICSOne expression of human nature is the natural desire for aesthetic beauty. For Hume--as for many of the Scottish philosophers--the aesthetics of "taste" was closely related to the moral sense of beauty. The standards for both aesthetics and morality are "qualities of mind useful or agreeable to ourselves or others." Although both aesthetic taste and moral taste vary somewhat across individuals and societies, there is a universal standard of taste rooted in the "original structure of the internal fabric" of human nature.

The importance of aesthetic taste in human evolution is evident in the evolutionary theorizing about the emergence of human art. Because human beings are unique in their capacity for symbolism, and because art is one evident manifestation of that symbolism, the earliest evidence of art (as in prehistoric cave paintings and figurines) serves as signs of the transition to fully human minds.

Contemporary exponents of evolutionary psychology have begun to formulate Darwinian theories of art in general and literary art in particular.

(10) THE DARWINIAN FUTURE OF HUMAN NATUREThe historical science of human nature as developed by Hume and Darwin allows us to see the emergence of human nature in the past and the present, because we have a record of human experience for the past and the present. But the future is undetermined, because we have no experience of the future. Consequently, we have no cosmic view of the whole of history, which would require a providential vision of the historical whole as a narrative of past, present, and future, which comes through the Biblical view of history and the Hegelian philosophy of history as dependent on the Biblical view.

It does seem, however, from the Humean and Darwinian view of past extinctions of species that the human species will eventually go extinct. For many people, this is deeply disturbing.

We can foresee that the conditions for life on earth are so fragile that no matter what human beings do, eventually changes in the climate of the earth or in the flow of energy from the sun will make human life impossible.

Some people foresee the emergence of transhuman life--perhaps robotic androids into which we might download our accumulated knowledge and self-awareness. But whether that would be either possible or desirable is open to question.

In any case, we must wonder whether a science of human nature that affirms the contingency of human life rather than its eternity can satisfy us.

Monday, May 18, 2009

President Obama's commencement speech at the University of Notre Dame and the controversy surrounding it remind us that religion cannot settle moral disputes.

In the debate over abortion and embryonic stem cell research, Obama says, we must look for "common ground" that goes beyond religious belief, because our disagreement over religion makes it impossible to settle this debate purely on religious grounds. The more general point that Obama has made in much of his rhetoric is the need for finding moral grounds for discussing public issues where religious diversity would create irresolvable disagreement.

In making such an argument, Obama revives a theme that goes back to the American constitutional founding. Most of the American founders--particularly at the Constitutional Convention of 1787--were not Christians. Moreover, they saw no way to organize the American regime as based on religious belief, because they saw too much diversity of religious belief, and because they wanted to avoid the religious warfare that had run through European history.

Consequently, they had to appeal to a natural moral experience that did not depend on religious doctrines. They could allow for a multiplicity of religious sects as long as all of those sects agreed in their moral teaching. Like Hume, the Founders saw morality as rooted in natural moral sentiments and natural moral judgments.

Don't we see this need for natural moral experience independent of religious belief in the debate over abortion and stem cell research? Religion cannot resolve the debate. Catholics appeal to the supreme authority of the Church. But non-Catholics cannot accept such authority. Protestants appeal to their individual religious consciences. But this does not persuade those who disagree with them. One might think that all Biblical believers could look to the Bible for answers. But the Bible never says that human life begins at conception. In fact, the Popes have admitted that the Catholic Church's condemnation of abortion as murder cannot be based on Biblical authority.

So, as I have argued in previous posts, we must rely on our natural moral experience as expressed in moral sentiments, moral traditions, and moral judgments.

Thursday, May 14, 2009

Adnan Oktar is a Turkish writer who uses the pen name Harun Yahya. He has become internationally famous as an Islamic critic of Darwinian evolution who denounces Darwinism as unscientific and atheistic in its denial of Allah as the Creator of everything.

Denyse O'Leary is a writer who promotes "intelligent design theory" at Bill Dembski's website--"Uncommon Descent." She has posted an interview with Oktar. She identifies him as a "Turkish Darwin doubter," and she praises one of his books as "the most succinct and comprehensive of the critiques of overblown claims for Darwinian evolution that I have ever read."

This might seem strange to anyone who knows that Oktar is a vehement critic not only of Darwinism but also of intelligent design theory. He exposes intelligent design theory, particularly as developed by Michael Behe, as a product of a Masonic conspiracy for promoting atheism and Deism.

This is a consequence of the deceptive rhetorical strategy employed by the proponents of intelligent design theory. On the one hand, they need to appeal to religious believers by conveying the message that the "intellient designer" is you know who. On the other hand, they insist that their reasoning is purely scientific and therefore not religious at all. But Behe pushes the scientific argument so hard that he ends up denying that Biblical theology has any scientific basis. I have written about that here and here. It is not surprising, therefore, that a Muslim creationist like Oktar denounces Behe and other intelligent design proponents. But then O'Leary shows the confusion in all of this by praising Oktar as a "Darwin doubter" who should be on the side of intelligent design!

There are complications in the story of Oktar that I won't take up here, because I don't know enough to judge his case. Some of the charges against him include the claim that he has led a cult whose members regularly have sex with girls under the age of 18. But they claim that this is permissible under Islamic law because they do not have "real sexual intercourse" but only "anal and oral sex."

It's good that these folks haven't been corrupted by Darwinian materialism!

Wednesday, May 13, 2009

Metaphysical conservatives believe that morality is impossible if it is not rooted in some religious belief in a transcendent moral order. Darwinian conservatives believe that morality is rooted in a natural moral sense, and so while religious belief can sometimes reinforce morality, there is a natural morality that can stand on its own even without religious belief. Tocqueville is often cited by the metaphysical conservatives like Carson Holloway and Lawler as supporting their belief that morality is impossible without religion. But I suggest that Tocqueville is more in the tradition of Cicero, Hume, and Burke in believing that religion is to be judged by how well it supports natural morality regardless of whether religious doctrines are true or not. We can judge the practical truth of religion as conforming to "civil religion" even when we are skeptical of religion's metaphysical claims.

Lawler's response to these claims is confusing. He says that Tocqueville agrees with metaphysical conservatives like himself who believe "that religious belief can actually be true." But then he says that Tocqueville "was not actually a Christian believer." I agree with Lawler on this latter point, because I read his letter to Madame Swetchine (February 26, 1857) as describing his loss of faith at age 16. Tocqueville does, however, suggest that he held onto some vague notions of God and an afterlife, indicating some kind of Deism.

In Democracy in America, Tocqueville makes it clear that he is more concerned with the moral truth of religion than with its theological truth. He is interested in "religion considered as a political institution." And for that purpose, it does not matter whether religion is true in its transcendent doctrines, as long as it teaches a proper morality. For example, Tocqueville suggests that the religious doctrine of reincarnation might be just as useful as the Christian doctrine of immortality. "Society has nothing to fear or hope from another life; what is most important for it is not that all citizens should profess the true religion but that they should profess religion."

In formulating the religious beliefs that support American democracy, Tocqueville follows the lead of Rousseau in the SOCIAL CONTRACT (IV, 8): "The existence of a powerful, intelligent, beneficent, foresighted, and providential divinity; the afterlife; the happiness of the just; the punishment of the wicked; the santity of the social contract and the laws. These are the positive dogmas. As for the negative ones, I limit them to a single one--intolerance."

Tocqueville judges the moral teachings of religion by a standard of moral virtue that stands independently of religion. That is clear, for example, when Tocqueville says that the democratic people in America suffer from a lack of grand ambition because they are too humble. For such people, "humility is never healthy . . . what they lack most, in my opinion, is pride. I would willingly surrender several of our petty virtues for that vice." It might seem odd that Tocqueville should have to recommend a particular "vice" in preference to certain "petty virtues." But that awkward position is forced on him by Christian ethics. To endorse pride as a virtue and to disparage humility as a vice, he would have to appeal to pre-Christian moral thought. To promote the human greatness displayed by men of grand ambitions, he would have to revive the pagan virtue of magnanimity--"greatness of soul." Here Tocqueville agrees with Hume who worried that the "monkish virtues" of Christianity--humility, mortification, self-denial, penance--were not really virtues at all.

Some of the commentators on Lawler's post indicate that the dangers of Darwinian science would have been avoided if the South had won the Civil War! This points to a big question about the moral teaching of biblical religion. Proslavery Southerners were able to cite the Bible as supporting slavery, because the Bible never clearly condemns slavery or calls for its abolition. For this reason, the Civil War created a theological crisis in which biblical believers could not rely on the Bible to give them proper moral instruction about the evils of slavery. In the division between North and South, as Lincoln said in the Second Inaugural, "both read the same Bible, and pray to the same God; and each invokes His aid against the other."

If morality is impossible without biblical religion--as the metaphysical conservatives insist--then we have no natural ground of morality by which we can judge the moral teaching of the Bible on slavery or any other issue. Hume and Darwin believed that we could see the injustice of slavery as contrary to our human nature and our natural moral sense. If we can appeal to such a natural morality, then we can see that any biblical teaching favoring slavery is mistaken, and we can correct it. But if there is no natural morality independent of biblical religion, then we have no ground for correcting the moral teaching of the Bible.

Tuesday, May 12, 2009

I have indicated that the debate over Darwinian conservatism shows the tension between metaphysical or transcendentalist conservatism and evolutionary or empirical conservatism. The metaphysical conservatives look to the tradition of Edmund Burke, Alexis de Tocqueville, and Russell Kirk. The evolutionary conservatives look to the tradition of David Hume, Adam Smith, and Friedrich Hayek. Metaphysical conservatives like Carson Holloway and Peter Lawler, for example, reject Darwinian conservatism because they fear that it denies the religious belief in a transcendent moral order that is required for any healthy morality. By contrast, those on the "secular right" look to Hume for a conservative view of moral order that does not require religious belief. Some of my posts on these issues can be found here, here, here, here, and here.

My graduate seminar on Hume this past semester has helped me to think through Hume's position in this debate. In particular, I have benefited from reading a paper on Hume's view of religion by one of my students--Ben Gross.

Hume is a vigorous critic of biblical religion. He elaborates the reasoning for rejecting any belief in miracles, divine providence, immorality of the soul, eternal rewards and punishments, and the argument from design for God's existence. He denigrates Christian moral teaching for its life-denying "monkish virtues." And he laments the violence and intolerance of Catholic superstition and Protestant enthusiasm. It is not surprising, therefore, that many people have concluded that Hume was an atheist who hoped for a future society without religious belief. That explains why all of Hume's writings were put on the Catholic Church's Index of Prohibited Books.

But even as he denies that there are any rational proofs for the supernatural doctrines of biblical religion, Hume indicates that reason cannot deny an appeal to faith beyond reason, which suggests that reason cannot refute revelation. And while he generally attacks the argument from design as proof for the biblical God, he sometimes suggests that the intelligent order of the universe might well point to some divine First Cause as the basis for a philosophical theism or "true religion."

Moreover, Hume's History of England shows this same ambivalence about biblical religion. He scorns the violence and foolishness of religious fanaticism in English history. But he also recognizes that Protestantism in general and the Puritans in particular promoted the English spirit of liberty.

In Hume's "Idea of a Perfect Commonwealth" in his Essays, Hume sketched a plan for the most perfect form of government. (Douglas Adair surveyed the evidence for concluding that James Madison and Alexander Hamilton were decisively influenced by this plan in their conception of the United States Constitution.) His plan includes an established Presbyterian religion. His likely reason for doing this is indicated in his History: during the period of the English Commonwealth, the Presbyterians were moderates who were opposed to the episcopal authority of the Anglican Church, on the one hand, but also opposed to the religious anarchy of the Puritan independents. This suggests the importance for Hume of a moderate form of Protestant religious authority.

In his Enquiry Concerning Human Understanding (section 11), Hume criticizes the biblical doctrines of immortality with eternal rewards and punishments from a providential God. He indicates that morality does not require such religious beliefs for those who reason well about nature. But he also notes that such religious beliefs might be necessary to reinforce morality for the multitude of human beings who do not reason well.

Metaphysical conservatives like Lawler and Holloway who appeal to Tocqueville's account of religion in America fail to see how close Tocqueville is to Hume on this issue. Speaking of "religion considered as a political institution," Tocqueville in Democracy in America indicates that the moral and political effects of religious beliefs are important for social order regardless of whether those beliefs are true or not. Tocqueville's reasoning about the salutary political effects of religious belief conforms largely to Rousseau's teaching about the importance of "civil religion."

Thus do Hume and Tocqueville belong to a long conservative tradition--stretching from Cicero to Burke to Hayek--that recognizes the political importance of religious belief for the multitude of human beings whose morality might be reinforced by such belief.

Charles Darwin belongs to that same tradition, because he saw the influence of religious habits and teachings in shaping moral experience. But Darwin also saw that morality was rooted in an evolved human nature that provided a natural ground for morality independent of religious belief.

Friday, May 08, 2009

The three conflicting views of human nature--materialism, interactionism, supernaturalism--run throughout the history of natural science from Socrates to the present. In Plato's Phaedo, Socrates talks with his friends while awaiting execution. He recounts that as a young man he thought that a scientific investigation of nature would explain the cause of everything. He had hoped to explain the physical causes of all things coming into being and passing away, including the causes of animal life and the causes of human thought. He became frustrated when he found that a complete science of nature as governed by physical causes was beyond his grasp. To explain the world, Socrates insists, it is necessary to understand both physical causes and mental causes. For example, to explain why Socrates is sitting here awaiting his execution, one might describe the physical mechanisms in his body--the bones, muscles, ligaments, and so on--that control his movement. But while these physical causes are necessary in explaining why he is sitting here, they are not sufficient. It is also necessary to explain how Socrates made up his mind to accept his punishment, because this mental decision controls his physical body.

Socrates appeals to a person's ordinary experience of making up one's mind and then freely choosing to act according to that conscious mental decision. This leads people to think that the mind has a power to act that changes the physical causes of the body. Holding oneself and others morally and legally responsible for their conduct assumes that freedom of thought and choice.

This kind of Socratic thinking has led many people to conclude that human nature is characterized by a complex interaction of mind and body, mental and physical causes. The human mind acts on the human body, or the mind exerts an immaterial power that is not reducible to the material causes of the body.

Socrates was responding to a materialist or physicalist tendency that became a strong tradition in Western science. That materialist tradition gained great power during the scientific revolution of the sixteenth and seventeenth centuries. Proponents of the new science saw the universe as a mechanism that could be explained by mechanical laws working through physical causes. It seemed that much of human nature could be explained similarly without invoking an immaterial soul.

Thomas Hobbes saw nature as matter in motion governed by laws of motion such as those discovered by Galileo. Animal life, then, including human life, is "but a motion of limbs." "For what is the heart, but a spring; and the nerves, but so many strings; and the joints, but so many wheels, giving motion to the whole body." Animal motion is driven mechanically by selfish passions that goad animals to seek pleasure and avoid pain. Although human beings are moved by some of the same selfish passions, humans are unique in their capacity for reason and speech. Yet even this uniquely human intellectual capacity can be understood mechanistically as the computational manipulation of informational signals. (This is why some proponents of "artificial intelligence" today see Hobbes as the founder of the modern view of thought as computational and thus, in principle, replicable in computers and robots.)

Hobbes's materialist science of the soul seemed to be confirmed by Thomas Willis's studies of the brain. Working in England as the same time as Hobbes, Willis compared the anatomy of the human brain with that of other animal brains and combined experiments on brains with medical observations of brain-damaged patients to develop what he called "neurology." He reached five broad conclusions. First, all mental experience arises from the motion of "animal spirits" undergoing chemical changes in the brain. Second, different parts of the brain have different functions. Third, the human brain resembles other animal brains, particularly those of monkeys and apes. Fourth, this science of neurology could be used by medical doctors to cure diseases of the brain through the use of drugs that would alter the chemistry of the brain. Fifth, all this supports the general view of the "mechanical philosophy" of the seventeenth century that the human body and brain are both machines explainable by mechanical laws.

Although Willis was mistaken about many details, his broad conclusions are supported by modern neuroscience. What Willis called animal spirits can be understood as electrical and chemical signaling between neurons. Willis's observation that the brain has specialized functions has been elaborated by studies of the ways neurons are organized into modular networks with distinct functions. Willis's claim that the human brain resembles the brains of other animals can be explained by evolutionary biology. His hope that drugs could cure the diseases of the soul seems to have been fulfilled by modern psychopharmacology in its use of drugs to treat mental disorders and enhance mental function. Finally, Willis's mechanistic account of the mind has been elaborated with computer models of the mind as an information-processing system.

But while it might appear that the science of the human brain initiated by Willis proves Hobbes's materialist view of the soul, Willis was not in fact a strict materialist, because he believed that his science showed the existence of two souls. The "sensitive soul" found in all animals was purely material and therefore vulnerable to physical diseases. The "rational soul" found only in human beings was immaterial and immortal, although it depended on the sensitive soul. So Willis's account of human nature was interactionist in that he thought the material brain and the immaterial soul mutually influenced each other. He was also a supernaturalist in that he thought the immaterial soul was created by God to be immortal. (Still, it's hard to decide whether he was sincere in this, or whether he was professing supernaturalism to protect himself against scandal.)

Today, many scientists argue that natural science sustains a purely materialist view of human nature and refutes any belief in the human soul as immaterial or immortal. But some neuroscientists--for example, Wilder Penfield and John Eccles--have defended Willis's interactionist view of the mind as an immaterial cause that can act on the brain. Eccles, a Nobel-prize-winning neuroscientist, argued that modern neuroscience is compatible with belief in the self-conscious mind as an immaterial power for thinking and choosing.

What difference do these debates over the science of mind-brain interaction make for an understanding of human nature and morality? Those who argue for an immaterial soul agree with Socrates that the capacity of the mind to act outside the laws of physical nature is necessary for moral freedom. They warn against scientific materialism as a denial of free will that would make it impossible to hold people morally responsible for their conduct. They also warn that a materialistic view of human nature would promote a Hobbesian hedonism that would deprive human life of any moral dignity. And if the ultimate end of modern science is the conquest of nature, people might be tempted to use the technological power of science to alter human nature itself in ways that would be dehumanizing. This seems to confirm the fears of many people that modern science, insofar as it promotes a materialist view of human nature, subverts traditional morality. (This is the argument of people like Leon Kass.)

And yet, as I have often argued on this blog, scientific reasoning about the human mind can support traditional morality by showing how it is rooted in the human brain. Darwin showed how a natural moral sense could be implanted in human nature by evolutionary history. As naturally social animals, human beings evolved to have a natural sense of right and wrong that would support social cooperation on the basis of ties of kinship, reciprocity, and mutuality. To reinforce this cooperative behavior, they were endowed with emotional propensities to moral emotions such as love, guilt, and indignation, and they were also endowed with the intellectual capacity to formulate social norms of cooperation rooted in those moral emotions.

Some neuroscientists have found that moral experience depends on the moral emotions sustained by the emotional control centers of the brain and on the moral reasoning carried out in the prefrontal cortex of the brain. If these parts of the brain are not functioning normally, people cannot act as moral beings. For example, psychopathic criminals apparently have an abnormality in their brain circuitry that prevents them from feeling the moral emotions that support the moral conduct of normal human beings. Such scientific research suggests that morality is part of the biological nature of human beings.

A selection of some of my previous posts on the neuroscience of the mind, morality, and freedom can be found here, here, here, here, here, here, and here.

Thursday, May 07, 2009

In his Ten Theories of Human Nature, Leslie Stevenson argues that theories of human nature require theories about the world, human beings, what might be wrong with human beings, and how anything that is wrong might be corrected. Even those who deny any essential human nature in favor of a historical or cultural construction of human nature have views about what kinds of beings human beings are and their place in the world.

Premodern theories of human nature generally viewed humans as properly subordinated to a larger order so that even though people might rebel against that order, they are called upon to learn to control such rebellion by means of ethical or religious practices. By contrast, modern theories tend to see human beings as unjustly limited by the larger order of things, and thus they are encouraged to overcome those limitations, often by means of science or technology.

For Plato, in a famous analogy from the Republic, the human soul is presented as composed of three parts: appetite, spiritedness, and reason. Disorder arises whenever appetite or spiritedness departs from the rule of reason. Similarly, for Aristotle in the Nicomachean Ethics, human lives can be directed to pleasure, politics, or knowledge, but the perfection of human nature comes from the rule of reason--practical reasoning or theoretical reasoning. Thomas Aquinas further develops this perspective by arguing that the lawful order of nature is manifest in human nature as natural inclinations to life, affective sociability, and the rational pursuit of politics and philosophy. Although the Jewish, Christian, and Islamic views of human nature seek in some measure to subordinate reason to faith in revelation, that faith, like reason, ultimately places boundaries on appetitive, political, and even scientific activities. Similar views can be found in the Asian religious and philosophical traditions associated with Hinduism and Buddhism.

Typically modern theories of human nature such as those of Thomas Hobbes and John Locke, even when they offer a materialist and mechanistic analysis of the workings of human nature, argue that humans are improperly constrained by the state of nature. In Hobbes's famous description, the state of nature is one in which human life is "solitary, poor, nasty, brutish, and short," a condition from which human beings must escape to enjoy a civilized life.

What can science contribute to the assessment of these diverse theories of human nature? One scientific debate concerns the relative influences of nature and nurture in human affairs. Another concerns the degrees of rationality or irrationality in human decisions and actions. Among the most fundamental questions is whether there is something--a rational or transrational mind or soul--that cannot be accounted for by the material causes that govern all other beings in the natural world.

Materialism (or physicalism) is the position that the physical world is self-contained or closed, so that the physical world can be explained only through physical causes and effects. In considering human nature, a materialist would say that human beings must be explained as purely material mechanisms, as physical bodies governed exclusively by physical causes. Consequently, the human mind should be understood as an activity of the physical brain. All the thinking, feeling, and willing of the conscious self must be determined totally by the body, particularly the brain and nervous system.

Against such a materialist view of human nature, a dualist would argue that mind is not fully reducible to body, that the mind can act as an immaterial cause on the material brain. An interactionist dualist would agree that the mind depends on the brain as its necessary but not sufficient condition. So, if some part of the brain is damaged or ceases to function normally, this can interfere with mental activity. Still, as long as the mind is supported by normal brain activity, the mind can exert its independent power over the brain. When people act through conscious thinking and willing, they use their immaterial minds to control their material brains. A religious believer might go further and claim that the immaterial mind was created by an immaterial God, and thus the mind or soul is supernatural. This supernatural character of the soul could render it immortal, so that the human soul could survive the death of the human body, although orthodox Christianity teaches that immortality requires the resurrection of the body.

There are, then, at least three fundamentally distinct views of human nature that are based on three views of the relationship between mind and body. The materialist believes that the mind has no immaterial power to act on the body. The interactionist believes that the immaterial mind interacts with a material body. The supernaturalist believes that the immaterial mind is supernatural and immortal. Each of these views implies more general perspectives on human beings and their place in nature.

Monday, May 04, 2009

Over this past weekend, The University of Chicago's Basic Program of Liberal Education sponsored a weekend study retreat at the Illinois Beach Resort in Zion, Illinois, on "Charles Darwin: A Continuing Challenge." Participating in the program brought back memories for me of my years teaching in the Basic Program when I was a graduate student at the University of Chicago in the 1970s.

On Friday evening, I lectured on "Does Darwin Support or Subvert Morality?" On Saturday, Jack Melsheimer lectured on "What Does 'Species' Mean in the Origin of Species?"; and Michaelangelo Allocca lectured on "More Fun than a Barrel of Monkey Trials: Darwin's Complex Relationship with Religion." The only part of the program that I regrettably missed was Richard Milner's performance Saturday night--"Charles Darwin: Live and in Concert." On Sunday morning, the final lecture was by George Anastaplo--"On the Suggestive Origins of Darwin and Lincoln."

The lectures and discussions gave me much to ponder. In particular, I found myself thinking more about questions that have come up on this blog about whether Darwinian science can adequately explain the existential questions that human beings ask themselves.

The "existential questions" are questions about the meaning of death, depravity, and transcendent longing. Why do we have to die? Is death the end of our personal existence? Or can we somehow live on? Why do we see so much depravity in human life as human beings inflict suffering on themselves and others? And why do human beings strive for some transcendent purpose beyond their transient mortal lives?

Can Darwinian science--can any science--account for and respond to such questions? Or are such questions too "personal"--too much tied up with our self-centered personal concerns--to be answerable by a seemingly impersonal science of nature and human nature?

A Christian (like Augustine, for example) would say that such questions are uniquely human and that they point to the supernatural. The only answer to death is immortality. The only answer to depravity is redemption. And the only answer to our transcendent longings is eternal union with God.

As I have indicated in some previous posts, Peter Augustine Lawler has criticized my "Darwinian natural right" as failing to explain or satisfy this existential anxiety of human beings. (It's fitting that "Augustine" is his middle name!)

There really are two sets of issues here. First, can Darwinian science explain why human beings ask such existential questions? Second, can it answer those questions?

Christians like Augustine and Lawler will say that no purely natural science or philosophy can account for or answer such questions, because the questions show a yearning of the human soul to transcend the natural world--a longing for some spiritual realm beyond nature--which cannot be understood or satisfied by any purely natural knowledge. To understand this longing, we must have religious faith--we must believe in order to understand. To satisfy this longing, we must see by faith our future redemption.

It is not surprising, therefore, that Lawler and others have objected to the Darwinian naturalism conveyed in the last paragraph of Darwinian Natural Right:

"The idea of Darwinian natural right offers us one way of understanding our human place in nature. We are neither mindless machines nor disembodied spirits. We are animals. As animals, we display the animate powers of nature for movement, desire, and awareness. We move to satisfy our desires in the light of our awareness of the world. We are a unique species of animal, but our distinctively human traits--such as symbolic speech, practical deliberation, and conceptual thought--are elaborations of powers shared in some form with other animals. Our powers for habituation and learning allow us to alter our natural environments, but even these powers are extensions of the behavioral flexibility shown by other animals. So even if the natural world was not made for us, we were made for it, because we are adapted to live in it. We have not been thrown into nature from some place far away. We come from nature. It is our home."

Lawler rightly sees that this paragraph is a direct attack on his Heideggerian existentialism and Gnostic dualism. Like other Gnostic Christians, Lawler rejects what Heidegger called "biologism"--the idea that we can fully explain human beings through their biological nature. By contrast, Gnostic Christians and Heideggerian existentialists insist on a radical dualism of matter and mind in which the human mind or soul utterly transcends the human body. Indeed, in the original Gnostic vision, the natural body and all of nature is a prison for the human spirit that strives to escape to a transcendent world beyond nature.

Against this, I argue for the idea of embodiment--that matter and mind are inextricably bound up together. The science of human nature, therefore, must explain this psychophysical unity of human experience. Orthodox Christianity affirms this psychophysical unity in doctrines such as the incarnation of Christ and the resurrection of the body, which recognizes that to be a human being is to be a body that thinks. Radical dualism--like that of the Gnostics--denies this unity of body and mind.

This radical dualism runs through much of modern thought--from Descartes to Pascal to Heidegger. Darwinian science denies this dualism by explaining mind as an emergent property of matter.

Darwin acknowledged that human beings were unique in their propensity for reflecting on the meaning of life and death. Explaining how such human self-awareness arises by emergent evolution in the primate brain is crucial to the fulfillment of a Darwinian science.

But could such a perfected Darwinian science ever fully explain the despair that Darwin felt in response to the death of his beloved daughter Annie? Or is such experience too personal to be properly handled by science? Does religion provide a more adequate response to such experiences?